Vertical grow tower conveyance system for controlled environment agriculture including tower shuttle

ABSTRACT

A vertical farming structure having vertical grow towers and associated conveyance mechanisms for moving the vertical grow towers through a controlled environment, while being exposed to controlled conditions, such as lighting, airflow, humidity and nutritional support. The present disclosure describes a reciprocating cam mechanism that provides a cost-efficient mechanism for conveying vertical grow towers in the controlled environment. The reciprocating cam mechanism can be arranged to increase the spacing of the grow towers as they are conveyed through the controlled environment to index the crops growing on the towers. The present disclosure also describes a tower shuttle mechanism that provides operational flexibility by decoupling the loading and unloading operations of the grow towers from the vertical farming structure and, therefore, allowing multiple grow towers to be extracted for harvesting in a batch process before loading new grow towers into the vertical farming structure in a separate process.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to U.S. provisional applicationSer. No. 62/903,579 filed Sep. 20, 2019, which is incorporated herein byreference for all purposes.

BACKGROUND Field of the Disclosure

The disclosure relates generally to controlled environment agricultureand, more particularly, to loading and conveyance systems for verticalplant production systems.

Description of Related Art

The subject matter discussed in the background section should not beassumed to be prior art merely as a result of its mention in thebackground section. Similarly, a problem mentioned in the backgroundsection or associated with the subject matter of the background sectionshould not be assumed to have been previously recognized in the priorart. The subject matter in the background section merely representsdifferent approaches, which in and of themselves may also correspond toimplementations of the claimed technology.

During the twentieth century, agriculture slowly began to evolve from aconservative industry to a fast-moving high-tech industry. Global foodshortages, climate change and societal changes drove a move away frommanually-implemented agriculture techniques toward computer-implementedtechnologies. In the past, and in many cases still today, farmers onlyhad one growing season to produce the crops that would determine theirrevenue and food production for the entire year. However, this ischanging. With indoor growing as an option and with better access todata processing technologies, the science of agriculture has become moreagile. It is adapting and learning as new data is collected and insightsare generated.

Advancements in technology are making it feasible to control the effectsof nature with the advent of “controlled environment agriculture.”Improved efficiencies in space utilization, lighting, and a betterunderstanding of hydroponics, aeroponics, crop cycles, and advancementsin environmental control systems have allowed humans to better recreateenvironments conducive for agriculture crop growth with the goals ofgreater yield per square foot, better nutrition and lower cost.

US Patent Publication Nos. 2018/0014485 and 2018/0014486, both assignedto the assignee of the present disclosure and incorporated by referencein their entirety herein, describe environmentally controlled verticalfarming systems. The vertical farming structure (e.g., a verticalcolumn) may be moved about an automated conveyance system in an open orclosed-loop fashion, exposed to precision-controlled lighting, airflowand humidity, with ideal nutritional support.

US Patent Pub. No. US 2017/0055460 (“Brusatore”) describes a system forcontinuous automated growing of plants. A vertical array of plantsupporting arms extends radially from a central axis. Each arm includespot receptacles which receive the plant seedling, and liquid nutrientsand water. The potting arms are rotated beneath grow lamps andpollinating arms. However, the spacing between plants appears to befixed.

SUMMARY OF THE DISCLOSURE

The present disclosure is directed to a vertical farming structurehaving vertical grow towers and associated conveyance mechanisms formoving the vertical grow towers through a controlled environment, whilebeing exposed to controlled conditions, such as lighting, airflow,humidity and nutritional support. The present disclosure describes areciprocating cam mechanism that provides a cost-efficient mechanism forconveying vertical grow towers in the controlled environment. Thereciprocating cam mechanism can be arranged to increase the spacing ofthe grow towers as they are conveyed through the controlled environmentto index the crops growing on the towers. The present disclosure alsodescribes a tower shuttle mechanism that provides operationalflexibility by decoupling the loading and unloading operations of thegrow towers from the vertical farming structure and, therefore, allowingmultiple grow towers to be extracted for harvesting in a batch processbefore loading new grow towers into the vertical farming structure in aseparate process.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a functional block diagram illustrating an example controlledenvironment agriculture system.

FIG. 2 is a perspective view of an example controlled environmentagriculture system.

FIGS. 3A and 3B are perspective views of an example grow tower.

FIG. 4A is a top view of an example grow tower; FIG. 4B is aperspective, top view of an example grow tower; FIG. 4C is an elevationview of a section of an example grow tower; and FIG. 4D is a sectional,elevation view of a portion of an example grow tower.

FIG. 5A is a perspective view of a portion of an example grow line; andFIG. 5B is a perspective view of an example tower hook.

FIG. 6 is an exploded, perspective view of a portion of an example growline and reciprocating cam mechanism.

FIG. 7A is a sequence diagram illustrating operation of an examplereciprocating cam mechanism; and FIG. 7B illustrates an alternative camchannel including an expansion joint.

FIG. 8 is a profile view of an example grow line and irrigation supplyline.

FIG. 9 is a side view of an example tower hook and integrated funnelstructure.

FIG. 10 is a profile view of an example grow line.

FIG. 11A is perspective view of an example tower hook and integratedfunnel structure; FIG. 11B is a section view of an example tower hookand integrated funnel structure; and FIG. 11C is a top view of anexample tower hook and integrated funnel structure.

FIG. 12 is an elevation view of an example carriage assembly.

FIG. 13 is a perspective view of a grow line and an example towershuttle mechanism.

FIG. 14 is an elevation view of an example tower shuttle mechanism.

FIG. 15A is a side elevation view of an example tower shuttle mechanism;and FIG. 15B is a sectional view illustrating the carriage assembly ofthe example tower shuttle mechanism.

FIG. 16 is a side elevation view of an alternative tower shuttlemechanism.

DETAILED DESCRIPTION

The present description is made with reference to the accompanyingdrawings, in which various example embodiments are shown. However, manydifferent example embodiments may be used, and thus the descriptionshould not be construed as limited to the example embodiments set forthherein. Rather, these example embodiments are provided so that thisdisclosure will be thorough and complete. Various modifications to theexemplary embodiments will be readily apparent to those skilled in theart, and the generic principles defined herein may be applied to otherembodiments and applications without departing from the spirit and scopeof the disclosure. Thus, this disclosure is not intended to be limitedto the embodiments shown, but is to be accorded the widest scopeconsistent with the principles and features disclosed herein.

The following describes a vertical farm production system configured forhigh density growth and crop yield. FIGS. 1 and 2 illustrate acontrolled environment agriculture system 10 according to one possibleembodiment of the invention. At a high level, the system 10 may includean environmentally-controlled growing chamber 20, a vertical towerconveyance system 200 disposed within the growing chamber 20 andconfigured to convey grow towers 50 with crops disposed therein, and acentral processing facility 30. The crops or plants species that may begrown may be gravitropic/geotropic and/or phototropic, or somecombination thereof. The crops or plant species may vary considerablyand include various leaf vegetables, fruiting vegetables, floweringcrops, fruits and the like. The controlled environment agriculturesystem 10 may be configured to grow a single crop type at a time or togrow multiple crop types concurrently.

The system 10 may also include conveyance systems for moving the growtowers in a circuit throughout the crop's growth cycle, the circuitcomprising a staging area configured for loading the grow towers 50 intoand out of the vertical tower conveyance mechanism 200.

The central processing system 30 may include one or more conveyancemechanisms for directing grow towers 50 to stations in the centralprocessing system 30—e.g., stations for loading plants into, andharvesting crops from, the grow towers 50. The vertical tower conveyancesystem 200, within the growing chamber 20, is configured to support andtranslate one or more grow towers 50 along grow lines 202. Each growtower 50 is configured for containing plant growth media that supports aroot structure of at least one crop plant growing therein. Each growtower 50 is also configured to releasably attach to a grow line 202 in avertical orientation and move along the grow line 202 during a growthphase. Together, the vertical tower conveyance mechanism 200 and thecentral processing system 30 (including associated conveyancemechanisms) can be arranged in a production circuit under control of oneor more computing systems.

The growth environment 20 may include light emitting sources positionedat various locations between and along the grow lines 202 of thevertical tower conveyance system 200. The light emitting sources can bepositioned laterally relative to the grow towers 50 in the grow line 202and configured to emit light toward the lateral faces of the grow towers50 that include openings from which crops grow. The light emittingsources may be incorporated into a water-cooled, LED lighting system asdescribed in U.S. Publ. No. 2017/0146226A1, the disclosure of which isincorporated by reference herein. In such an embodiment, the LED lightsmay be arranged in a bar-like structure. The bar-like structure may beplaced in a vertical orientation to emit light laterally tosubstantially the entire length of adjacent grow towers 50. Multiplelight bar structures may be arranged in the growth environment 20 alongand between the grow lines 202. Other lighting systems andconfigurations may be employed. For example, the light bars may bearranged horizontally between grow lines 202.

The growth environment 20 may also include a nutrient supply systemconfigured to supply an aqueous crop nutrient solution to the crops asthey translate through the growth chamber 20. As discussed in moredetail below, the nutrient supply system may apply aqueous crop nutrientsolution to the top of the grow towers 50. Gravity may cause thesolution travel down the vertically-oriented grow tower 50 and throughthe length thereof to supply solution to the crops disposed along thelength of the grow tower 50. The growth environment 20 may also includean airflow source configured to, when a tower is mounted to a grow line202, direct airflow in the lateral growth direction of growth andthrough an under-canopy of the growing plant, so as to disturb theboundary layer of the under-canopy of the growing plant. In otherimplementations, airflow may come from the top of the canopy ororthogonal to the direction of plant growth. The growth environment 20may also include a control system, and associated sensors, forregulating at least one growing condition, such as air temperature,airflow speed, relative air humidity, and ambient carbon dioxide gascontent. The control system may for example include such sub-systems asHVAC units, chillers, fans and associated ducting and air handlingequipment. Grow towers 50 may have identifying attributes (such as barcodes or RFID tags). The controlled environment agriculture system 10may include corresponding sensors and programming logic for tracking thegrow towers 50 during various stages of the farm production cycle and/orfor controlling one or more conditions of the growth environment. Theoperation of control system and the length of time towers remain ingrowth environment can vary considerably depending on a variety offactors, such as crop type and other factors.

As discussed above, grow towers 50 with newly transplanted crops orseedlings are transferred from the central processing system 30 into thevertical tower conveyance system 200. Vertical tower conveyance system200 moves the grow towers 50 along respective grow lines 202 in growthenvironment 20 in a controlled fashion, as discussed in more detailbelow. Crops disposed in grow towers 50 are exposed to the controlledconditions of growth environment (e.g., light, temperature, humidity,air flow, aqueous nutrient supply, etc.). The control system is capableof automated adjustments to optimize growing conditions within thegrowth chamber 20 to make continuous improvements to various attributes,such as crop yields, visual appeal and nutrient content. In addition, USPatent Publication Nos. 2018/0014485 and 2018/0014486 describeapplication of machine learning and other operations to optimize growconditions in a vertical farming system. In some implementations,environmental condition sensors may be disposed on grow towers 50 or atvarious locations in growth environment 20. When crops are ready forharvesting, grow towers 50 with crops to be harvested are transferredfrom the vertical tower conveyance system 200 to the central processingsystem 30 for harvesting and other processing operations.

Central processing system 30, as discussed in more detail below, mayinclude processing stations directed to injecting seedlings into towers50, harvesting crops from towers 50, and cleaning towers 50 that havebeen harvested. Central processing system 30 may also include conveyancemechanisms that move towers 50 between such processing stations. Forexample, as FIG. 1 illustrates, central processing system 30 may includeharvester station 32, washing station 34, and transplanter station 36.Harvester station 32 may deposit harvested crops into food-safecontainers and may include a conveyance mechanism for conveying thecontainers to post-harvesting facilities (e.g., preparation, washing,packaging and storage) that are beyond the scope of this disclosure.

Controlled environment agriculture system 10 may also include one ormore conveyance mechanisms for transferring grow towers 50 betweengrowth environment 20 and central processing system 30. In theimplementation shown, the stations of central processing system 30operate on grow towers 50 in a horizontal orientation. In oneimplementation, an automated pickup station 43, and associated controllogic, may be operative to releasably grasp a horizontal tower from aloading location, rotate the tower to a vertical orientation and attachthe tower to a transfer station for insertion into a selected grow line202 of the growth environment 20. On the other end of growth environment20, automated laydown station 41, and associated control logic, may beoperative to releasably grasp and move a vertically-oriented grow tower50 from a buffer location, rotate the grow tower 50 to a horizontalorientation and place it on a conveyance system for loading intoharvester station 32. In some implementations, if a grow tower 50 isrejected due to quality control concerns, the conveyance system maybypass the harvester station 32 and carry the grow tower to washingstation 34 (or some other station). The automated laydown and pickupstations 41 and 43 may each comprise a six-degrees of freedom roboticarm, such as a FANUC robot. The stations 41 and 43 may also include endeffectors for releasably grasping grow towers 50 at opposing ends.

Growth environment 20 may also include automated loading and unloadingmechanisms for inserting grow towers 50 into selected grow lines 202 andunloading grow towers 50 from the grow lines 202. In one implementation,the load transfer conveyance mechanism 47 may include a power and freeconveyor system that conveys carriages each loaded with a grow tower 50from the automated pickup station 43 to a selected grow line 202.Vertical grow tower conveyance system 200 may include sensors (such asRFID or bar code sensors) to identify a given grow tower 50 and, undercontrol logic, select a grow line 202 for the grow tower 50. Particularalgorithms for grow line selection can vary considerably depending on anumber of factors and is beyond the scope of this disclosure. The loadtransfer conveyance mechanism 47 may also include one or more linearactuators that pushes the grow tower 50 onto a grow line 202. Similarly,the unload transfer conveyance mechanism 45 may include one or morelinear actuators that push or pull grow towers from a grow line 202 ontoa carriage of another power and free conveyor mechanism, which conveysthe carriages 1202 from the grow line 202 to the automated laydownstation 41. FIG. 12 illustrates a carriage 1202 that may be used in apower and free conveyor mechanism. In the implementation shown, carriage1202 includes hook 1204 that engages hook 52 attached to a grow tower50. A latch assembly 1206 may secure the grow tower 50 while it is beingconveyed to and from various locations in the system. In oneimplementation, one or both of load transfer conveyance mechanism 47 andunload transfer conveyance mechanism 45 may be configured with asufficient track distance to establish a zone where grow towers 50 maybe buffered. For example, unload transfer conveyance mechanism 45 may becontrolled such that it unloads a set of towers 50 to be harvested untocarriages 1202 that are moved to a buffer region of the track. On theother end, automated pickup station 43 may load a set of towers to beinserted into growth environment 20 onto carriages 1202 disposed in abuffer region of the track associated with load transfer conveyancemechanism 47.

Grow Towers

Grow towers 50 provide the sites for individual crops to grow in thesystem. As FIGS. 3A and 3B illustrate, a hook 52 attaches to the top ofgrow tower 50. Hook 52 allows grow tower 50 to be supported by a growline 202 when it is inserted into the vertical tower conveyance system200. In one implementation, a grow tower 50 measures 5.172 meters long,where the extruded length of the tower is 5.0 meters, and the hook is0.172 meters long. The extruded rectangular profile of the grow tower50, in one implementation, measures 57 mm×93 mm (2.25″×3.67″). The hook52 can be designed such that its exterior overall dimensions are notgreater than the extruded profile of the grow tower 50. The foregoingdimensions are for didactic purposes. The dimensions of grow tower 50can be varied depending on a number of factors, such as desiredthroughput, overall size of the system, and the like.

Grow towers 50 may include a set of grow sites 53 arrayed along at leastone face of the grow tower 50. In the implementation shown in FIG. 4A,grow towers 50 include grow sites 53 on opposing faces such that plantsprotrude from opposing sides of the grow tower 50. Transplanter station36 may transplant seedlings into empty grow sites 53 of grow towers 50,where they remain in place until they are fully mature and ready to beharvested. In one implementation, the orientation of the grow sites 53are perpendicular to the direction of travel of the grow towers 50 alonggrow line 202. In other words, when a grow tower 50 is inserted into agrow line 202, plants extend from opposing faces of the grow tower 50,where the opposing faces are parallel to the direction of travel.Although a dual-sided configuration is preferred, the invention may alsobe utilized in a single-sided configuration where plants grow along asingle face of a grow tower 50.

U.S. application Ser. No. 15/968,425 filed on May 1, 2018 which isincorporated by reference herein for all purposes, discloses an exampletower structure configuration that can be used in connection withvarious embodiments of the invention. In the implementation shown, growtowers 50 may each consist of three extrusions which snap together toform one structure. As shown, the grow tower 50 may be a dual-sidedhydroponic tower, where the tower body 103 includes a central wall 56that defines a first tower cavity 54 a and a second tower cavity 54 b.FIG. 4B provides a perspective view of an exemplary dual-sided,multi-piece hydroponic grow tower 50 in which each front face plate 101is hingeably coupled to the tower body 103. In FIG. 4B, each front faceplate 101 is in the closed position. The cross-section of the towercavities 54 a, 54 b may be in the range of 1.5 inches by 1.5 inches to 3inches by 3 inches, where the term “tower cavity” refers to the regionwithin the body of the tower and behind the tower face plate. The wallthickness of the grow towers 50 maybe within the range of 0.065 to 0.075inches. A dual-sided hydroponic tower, such as that shown in FIGS. 4Aand 4B, has two back-to-back cavities 54 a and 54 b, each preferablywithin the noted size range. In the configuration shown, the grow tower50 may include (i) a first V-shaped groove 58 a running along the lengthof a first side of the tower body 103, where the first V-shaped grooveis centered between the first tower cavity and the second tower cavity;and (ii) a second V-shaped groove 58 b running along the length of asecond side of the tower body 103, where the second V-shaped groove iscentered between the first tower cavity and the second tower cavity. TheV-shaped grooves 58 a, 58 b may facilitate registration, alignmentand/or feeding of the towers 50 by one or more of the stations incentral processing system 30. U.S. application Ser. No. 15/968,425discloses additional details regarding the construction and use oftowers that may be used in embodiments of the invention. Anotherattribute of V-shaped grooves 58 a, 58 b is that they effectively narrowthe central wall 56 to promote the flow of aqueous nutrient solutioncentrally where the plant's roots are located. Other implementations arepossible. For example, a grow tower 50 may be formed as a unitary,single extrusion, where the material at the side walls flex to provide ahinge and allow the cavities to be opened for cleaning. U.S. applicationSer. No. 16/577,322 filed Sep. 20, 2019 which is incorporated byreference herein for all purposes, discloses an example grow tower 50formed by a single extrusion.

As FIGS. 4C and 4D illustrate, grow towers 50 may each include aplurality of cut-outs 105 for use with a compatible plug holder 158,such as the plug holder disclosed in any one of co-assigned andco-pending U.S. patent application Ser. Nos. 15/910,308, 15/910,445 and15/910,796, each filed on 2 Mar. 2018, the disclosures of which isincorporated herein for any and all purposes. As shown, the plug holders158 may be oriented at a 45-degree angle relative to the front faceplate 101 and the vertical axis of the grow tower 50. It should beunderstood, however, that tower design disclosed in the presentapplication is not limited to use with this particular plug holder ororientation, rather, the towers disclosed herein may be used with anysuitably sized and/or oriented plug holder. As such, cut-outs 105 areonly meant to illustrate, not limit, the present tower design and itshould be understood that the present invention is equally applicable totowers with other cut-out designs. Plug Holder 158 may be ultrasonicallywelded, bonded, or otherwise attached to tower face 101.

The use of a hinged front face plate simplifies manufacturing of growtowers, as well as tower maintenance in general and tower cleaning inparticular. For example, to clean a grow tower 50 the face plates 101are opened from the body 103 to allow easy access to the body cavity 54a or 54 b. After cleaning, the face plates 101 are closed. Since theface plates remain attached to the tower body 103 throughout thecleaning process, it is easier to maintain part alignment and to insurethat each face plate is properly associated with the appropriate towerbody and, assuming a double-sided tower body, that each face plate 101is properly associated with the appropriate side of a specific towerbody 103. Additionally, if the planting and/or harvesting operations areperformed with the face plate 101 in the open position, for thedual-sided configuration both face plates can be opened andsimultaneously planted and/or harvested, thus eliminating the step ofplanting and/or harvesting one side and then rotating the tower andplanting and/or harvesting the other side. In other embodiments,planting and/or harvesting operations are performed with the face plate101 in the closed position.

Other implementations are possible. For example, grow tower 50 cancomprise any tower body that includes a volume of medium or wickingmedium extending into the tower interior from the face of the tower(either a portion or individual portions of the tower or the entirety ofthe tower length. For example, U.S. Pat. No. 8,327,582, which isincorporated by reference herein, discloses a grow tube having a slotextending from a face of the tube and a grow medium contained in thetube. The tube illustrated therein may be modified to include a hook 52at the top thereof and to have slots on opposing faces, or one slot on asingle face.

Vertical Tower Conveyance System

FIG. 5A illustrates a portion of a grow line 202 in vertical towerconveyance system 200. In one implementation, the vertical towerconveyance system 200 includes a plurality of grow lines 202 arranged inparallel. As discussed above, automated loading and unloading mechanisms45, 47 may selectively load and unload grow towers 50 from a grow line202 under automated control systems. As FIG. 5A shows, each grow line202 supports a plurality of grow towers 50. In one implementation, agrow line 202 may be mounted to the ceiling (or other support) of thegrow structure by a bracket for support purposes. Hook 52 hooks into,and attaches, a grow tower 50 to a grow line 202, thereby supporting thetower in a vertical orientation as it is translated through the verticaltower conveyance system 200. A conveyance mechanism moves towers 50attached to respective grow lines 202.

FIG. 10 illustrates the cross section or extrusion profile of a growline 202, according to one possible implementation of the invention. Thegrow line 202 may be an aluminum extrusion. The bottom section of theextrusion profile of the grow line 202 includes an upward facing groove1002. As FIG. 9 shows, hook 52 of a grow tower 50 includes a main body53 and corresponding member 58 that engages groove 1002 as shown inFIGS. 5A and 8. These hooks allow the grow towers 50 to hook into thegroove 1002 and slide along the grow line 202 as discussed below.Conversely, grow towers 50 can be manually unhooked from a grow line 202and removed from production. This ability may be necessary if a crop ina grow tower 50 becomes diseased so that it does not infect othertowers. In one possible implementation, the width of groove 1002 (forexample, 13 mm) is an optimization between two different factors. First,the narrower the groove the more favorable the binding rate and the lesslikely grow tower hooks 52 are to bind. Conversely, the wider the groovethe slower the grow tower hooks wear due to having a greater contactpatch. Similarly, the depth of the groove, for example 10 mm, may be anoptimization between space savings and accidental fallout of towerhooks.

Hooks 52 may be injection-molded plastic parts. In one implementation,the plastic may be polyvinyl chloride (PVC), acrylonitrile butadienestyrene (ABS), or an Acetyl Homopolymer (e.g., Delrin® sold by DuPontCompany). The hook 52 may be solvent bonded to the top of the grow tower50 and/or attached using rivets or other mechanical fasteners. Thegroove-engaging member 58 which rides in the rectangular groove 1002 ofthe grow line 202 may be a separate part or integrally formed with hook52. If separate, this part can be made from a different material withlower friction and better wear properties than the rest of the hook,such as ultra-high-molecular weight polyethylene or acetal. To keepassembly costs low, this separate part may snap onto the main body ofthe hook 52. Alternatively, the separate part also be over-molded ontothe main body of hook 52.

As FIGS. 6 and 10 illustrate, the top section of the extrusion profileof grow line 202 contains a downward facing t-slot 1004. Linear guidecarriages 610 (described below) ride within the t-slot 1004. The centerportion of the t-slot 1004 may be recessed to provide clearance fromscrews or over-molded inserts which may protrude from the carriages 610.Each grow line 202 can be assembled from a number of separatelyfabricated sections. In one implementation, sections of grow line 202are currently modeled in 6-meter lengths. Longer sections reduce thenumber of junctions but are more susceptible to thermal expansion issuesand may significantly increase shipping costs. Additional features notcaptured by the Figures include intermittent mounting holes to attachthe grow line 202 to the ceiling structure and to attach irrigationlines. Interruptions to the t-slot 1004 may also be machined into theconveyor body. These interruptions allow the linear guide carriages 610to be removed without having to slide them all the way out the end of agrow line 202.

At the junction between two sections of a grow line 202, a block 612 maybe located in the t-slots 1004 of both conveyor bodies. This blockserves to align the two grow line sections so that grow towers 50 mayslide smoothly between them. Alternative methods for aligning sectionsof a grow line 202 include the use of dowel pins that fit into dowelholes in the extrusion profile of the section. The block 612 may beclamped to one of the grow line sections via a set screw, so that thegrow line sections can still come together and move apart as the resultof thermal expansion. Based on the relatively tight tolerances and smallamount of material required, these blocks may be machined. Bronze may beused as the material for such blocks due to its strength, corrosionresistance, and wear properties.

In one implementation, the vertical tower conveyance system 200 utilizesa reciprocating linear ratchet and pawl structure (hereinafter referredto as a “reciprocating cam structure or mechanism”) to move grow towers50 along a grow line 202. FIGS. 5A, 6 and 7 illustrate one possiblereciprocating cam mechanism that can be used to move grow towers 50across grow lines 202. Pawls or “cams” 602 physically push grow towers50 along grow line 202. Cams 602 are attached to cam channel 604 (seebelow) and rotate about one axis. On the forward stroke, the rotation islimited by the top of the cam channel 604, causing the cams 602 to pushgrow towers 50 forward. On the reserve or back stroke, the rotation isunconstrained, thereby allowing the cams to ratchet over the top of thegrow towers 50. In this way, the cam mechanism can stroke a relativelyshort distance back and forth, yet grow towers 50 always progressforward along the entire length of a grow line 202. A control system, inone implementation, controls the operation of the reciprocating cammechanism of each grow line 202 to move the grow towers 50 according toa programmed growing sequence. In between movement cycles, the actuatorand reciprocating cam mechanism remain idle.

The pivot point of the cams 602 and the means of attachment to the camchannel 604 consists of a binding post 606 and a hex head bolt 608;alternatively, detent clevis pins may be used. The hex head bolt 608 ispositioned on the inner side of the cam channel 604 where there is notool access in the axial direction. Being a hex head, it can be accessedradially with a wrench for removal. Given the large number of camsneeded for a full-scale farm, a high-volume manufacturing process suchas injection molding is suitable. ABS is suitable material given itsstiffness and relatively low cost. All the cams 602 for a correspondinggrow line 202 are attached to the cam channel 604. When connected to anactuator, this common beam structure allows all cams 602 to stroke backand forth in unison. The structure of the cam channel 604, in oneimplementation, is a downward facing u-channel constructed from sheetmetal. Holes in the downward facing walls of cam channel 604 providemounting points for cams 602 using binding posts 606.

Holes of the cam channel 604, in one implementation, are spaced at 12.7mm intervals. Therefore, cams 602 can be spaced relative to one anotherat any integer multiple of 12.7 mm, allowing for variable grow towerspacing with only one cam channel. The base of the cam channel 604limits rotation of the cams during the forward stroke. All degrees offreedom of the cam channel 604, except for translation in the axialdirection, are constrained by linear guide carriages 610 (describedbelow) which mount to the base of the cam channel 604 and ride in thet-slot 1004 of the grow line 202. Cam channel 604 may be assembled fromseparately formed sections, such as sections in 6-meter lengths. Longersections reduce the number of junctions but may significantly increaseshipping costs. Thermal expansion is generally not a concern because thecam channel is only fixed at the end connected to the actuator. Giventhe simple profile, thin wall thickness, and long length needed, sheetmetal rolling is a suitable manufacturing process for the cam channel.Galvanized steel is a suitable material for this application.

Linear guide carriages 610 are bolted to the base of the cam channels604 and ride within the t-slots 1004 of the grow lines 202. In someimplementations, one carriage 610 is used per 6-meter section of camchannel. Carriages 610 may be injection molded plastic for low frictionand wear resistance. Bolts attach the carriages 610 to the cam channel604 by threading into over molded threaded inserts. If select cams 602are removed, these bolts are accessible so that a section of cam channel604 can be detached from the carriage and removed.

Sections of cam channel 604 are joined together with pairs of connectors616 at each joint; alternatively, detent clevis pins may be used.Connectors 616 may be galvanized steel bars with machined holes at 20 mmspacing (the same hole spacing as the cam channel 604). Shoulder bolts618 pass through holes in the outer connector, through the cam channel604, and thread into holes in the inner connector. If the shoulder boltsfall in the same position as a cam 602, they can be used in place of abinding post. The heads of the shoulder bolts 618 are accessible so thatconnectors and sections of cam channel can be removed.

In one implementation, cam channel 604 attaches to a linear actuator,which operates in a forward and a back stroke. A suitable linearactuator may be the T13-B4010MS053-62 actuator offered by Thomson, Inc.of Redford, Va.; however, the reciprocating cam mechanism describedherein can be operated with a variety of different actuators. The linearactuator may be attached to cam channel 604 at the off-loading end of agrow line 202, rather than the on-boarding end. In such a configuration,cam channel 604 is under tension when loaded by the towers 50 during aforward stroke of the actuator (which pulls the cam channel 604) whichreduces risks of buckling. FIG. 7A illustrates operation of thereciprocating cam mechanism according to one implementation of theinvention. In step A, the linear actuator has completed a full backstroke; as FIG. 7A illustrates, one or more cams 602 may ratchet overthe hooks 52 of a grow tower 50. Step B of FIG. 7A illustrates theposition of cam channel 604 and cams 602 at the end of a forward stroke.During the forward stroke, cams 602 engage corresponding grow towers 50and move them in the forward direction along grow line 202 as shown.Step C of FIG. 7A illustrates how a new grow tower 50 (Tower 0) may beinserted onto a grow line 202 and how the last tower (Tower 9) may beremoved. Step D illustrates how cams 602 ratchet over the grow towers 50during a back stroke, in the same manner as Step A. The basic principleof this reciprocating cam mechanism is that reciprocating motion from arelatively short stroke of the actuator transports towers 50 in onedirection along the entire length of the grow line 202. Morespecifically, on the forward stroke, all grow towers 50 on a grow line202 are pushed forward one position. On the back stroke, the cams 602ratchet over an adjacent tower one position back; the grow towers remainin the same location. As shown, when a grow line 202 is full, a new growtower may be loaded and a last tower unloaded after each forward strokeof the linear actuator. In some implementations, the top portion of thehook 52 (the portion on which the cams push), is slightly narrower thanthe width of a grow tower 50. As a result, cams 602 can still engagewith the hooks 52 when grow towers 50 are spaced immediately adjacent toeach other. FIG. 7A shows 9 grow towers for didactic purposes. A growline 202 can be configured to be quite long (for example, 40 meters)allowing for a much greater number of towers 50 on a grow line 202 (suchas 400-450). Other implementations are possible. For example, theminimum tower spacing can be set equal to or slightly greater than twotimes the side-to-side distance of a grow tower 50 to allow more thanone grow tower 50 to be loaded onto a grow line 202 in each cycle.

Still further, as shown in FIG. 7A, the spacing of cams 602 along thecam channel 604 can be arranged to effect one-dimensional plant indexingalong the grow line 202. In other words, the cams 602 of thereciprocating cam mechanism can be configured such that spacing betweentowers 50 increases as they travel along a grow line 202. For example,spacing between cams 602 may gradually increase from a minimum spacingat the beginning of a grow line to a maximum spacing at the end of thegrow line 202. This may be useful for spacing plants apart as they growto increase light interception and provide spacing, and, throughvariable spacing or indexing, increasing efficient usage of the growthchamber 20 and associated components, such as lighting. In oneimplementation, the forward and back stroke distance of the linearactuator is equal to (or slightly greater than) the maximum towerspacing. During the back stroke of the linear actuator, cams 602 at thebeginning of a grow line 202 may ratchet and overshoot a grow tower 50.On the forward stroke, such cams 602 may travel respective distancesbefore engaging a tower, whereas cams located further along the growline 202 may travel shorter distances before engaging a tower or engagesubstantially immediately. In such an arrangement, the maximum towerspacing cannot be two times greater than the minimum tower spacing;otherwise, a cam 602 may ratchet over and engage two or more grow towers50. If greater maximum tower spacing is desired, an expansion joint maybe used, as illustrated in FIG. 7B. An expansion joint allows theleading section of the cam channel 604 to begin traveling before thetrailing end of the cam channel 604, thereby achieving a long stroke. Inparticular, as FIG. 7B shows, expansion joint 710 may attach to sections604 a and 604 b of cam channel 604. In the initial position (702), theexpansion joint 710 is collapsed. At the beginning of a forward stroke(704), the leading section 604 a of cam channel 604 moves forward (asthe actuator pulls on cam channel 604), while the trailing section 604 bremains stationary. Once the bolt bottoms out on the expansion joint 710to an open position (706), the trailing section 604 of cam channel 604begins to move forward as well. On the back stroke (708), the expansionjoint 710 collapses to its initial position. During the back stroke, theleading section 604 a moves backward, while the trailing section remainsstationary, until the expansion joint reaches the initial, collapsedposition.

Other configurations for grow line 202 are possible. For example,although the grow line 202 illustrated in the various figures ishorizontal to the ground, the grow line 202 may be sloped at a slightangle, either downwardly or upwardly relative to the direction of towertravel. Still further, while the grow line 202 described above operatesto convey grow towers in a single direction, the grow line 202 may beconfigured to include multiple sections, where each section is orientedin a different direction. For example, two sections may be perpendicularto each other. In other implementations, two sections may run parallelto each other, but have opposite directions of travel, to form asubstantially u-shaped travel path. In such an implementation, a returnmechanism can transfer grow towers from the end of the first pathsection to the onload end of the second path section of the grow line.

Irrigation & Aqueous Nutrient Supply

FIG. 8 illustrates how an irrigation line 802 may be attached to growline 202 to supply an aqueous nutrient solution to crops disposed ingrow towers 50 as they translate through the vertical tower conveyancesystem 200. Irrigation line 802, in one implementation, is a pressurizedline with spaced-apart openings or holes disposed at the expectedlocations of the towers 50 (tower load positions) as they advance alonggrow line 202 with each movement cycle. For example, the irrigation line802 may be a PVC pipe having an inner diameter of 1.5 inches and holeshaving diameters of 0.125 inches. The irrigation line 802 may beapproximately 40 meters in length spanning the entire length of a growline 202. To ensure adequate pressure across the entire line, irrigationline 802 may be broken into shorter sections, each connected to amanifold, so that pressure drop is reduced. The apertures or holes maybe fitted with emitter structures, such as a nozzle or tube extendingdownwardly from the irrigation line 802.

As FIG. 8 shows, a funnel structure 902 collects aqueous nutrientsolution from irrigation line 802 and distributes the aqueous nutrientsolution to the cavity(ies) 54 a, 54 b of the grow tower 50 as discussedin more detail below. FIGS. 9 and 11A illustrate that the funnelstructure 902 may be integrated into hook 52. For example, the funnelstructure 902 may include a collector 910, first and second passageways912 and first and second slots 920. As FIG. 9 illustrates, thegroove-engaging member 58 of the hook may disposed at a centerline ofthe overall hook structure. The funnel structure 902 may include flangesections 906 extending downwardly opposite the collector 910 and onopposing sides of the centerline. The outlets of the first and secondpassageways are oriented substantially adjacent to and at opposing sidesof the flange sections 906, as shown. Flange sections 906 register withcentral wall 56 of grow tower 50 to center the hook 52 and providesadditional sites to adhere or otherwise attach hook 52 to grow tower 50.In other words, when hook 52 is inserted into the top of grow tower 50,central wall 56 is disposed between flange sections 906. In theimplementation shown, collector 910 extends laterally from the main body53 of hook 52.

As FIG. 11B shows, funnel structure 902 includes a collector 910 thatcollects nutrient fluid and distributes the fluid evenly to the innercavities 54 a and 54 b of tower through passageways 912. Passageways 912are configured to distribute aqueous nutrient solution near the centralwall 56 and to the center back of each cavity 54 a, 54 b over the endsof the plug holders 158 and where the roots of a planted crop areexpected. As FIG. 11C illustrates, in one implementation, the funnelstructure 902 includes slots 920 that promote the even distribution ofnutrient fluid to both passageways 912. For nutrient fluid to reachpassageways 912, it must flow through one of the slots 920. Each slot920 may have a V-like configuration where the width of the slot openingincreases as it extends from the substantially flat bottom surface 922of collector 910. For example, each slot 920 may have a width of 1millimeter at the bottom surface 922. The width of slot 920 may increaseto 5 millimeters over a height of 25 millimeters. The configuration ofthe slots 920 causes nutrient fluid supplied at a sufficient flow rateby irrigation line 802 to accumulate in collector 910, as opposed toflowing directly to a particular passageway 912, and flow through slots920 to promote even distribution of nutrient fluid to both passageways912.

In operation, irrigation line 802 provides aqueous nutrient solution tofunnel structure 902 that even distributes the water to respectivecavities 54 a, 54 b of grow tower 50. The aqueous nutrient solutionsupplied from the funnel structure 902 irrigates crops contained inrespective plug containers 158 as it trickles down. In oneimplementation, a gutter disposed under each grow line 202 collectsexcess water from the grow towers 50 for recycling.

Other implementations are possible. For example, the funnel structuremay be configured with two separate collectors that operate separatelyto distribute aqueous nutrient solution to a corresponding cavity 54 a,54 b of a grow tower 50. In such a configuration, the irrigation supplyline can be configured with one hole or aperture for each collector. Insome implementations, an emitter structure or nozzle may be attached toeach hole or aperture. In other implementations, the towers may onlyinclude a single cavity and include plug containers only on a singleface 101 of the towers. Such a configuration still calls for a use of afunnel structure that directs aqueous nutrient solution to a desiredportion of the tower cavity, but obviates the need for separatecollectors or other structures facilitating even distribution.

Tower Shuttle Mechanism

In the implementation described above in connection with FIG. 7A, when agrow line 202 is full, a new grow tower 50 may be loaded and a last growtower unloaded after each forward stroke of the linear actuatorassociated with the reciprocating cam mechanism. If the reciprocatingcam mechanism cycles without loading a grow tower 50 at each cycle, agap will be created preventing full utilization of the length of thegrow line 202. For certain operational purposes, it may be desirable tode-couple tower unloading and loading operations. In other words, it maybe desirable to cycle the reciprocating cam mechanism a number of timesto extract grow towers without injecting a new grow tower at each cycle.

For example, grow lines 202 can be quite long and thereby support alarge number of grow tower positions (such as 100-200 grow positions).In addition, a daily harvest may involve the extraction of 30-40 growtowers 50 in a single batch process. It may be desirable to haveoperating staff concentrate on offloading towers for harvesting in adaily or batch process and then concentrate on injecting new towers intovertical farming structure in a separate daily or batch process.

FIG. 13 illustrates an example tower shuttle mechanism 1300 that allowsfor injection of grow towers 50 at select positions along a grow line202 without cycling of the reciprocating cam mechanism. The towershuttle mechanism 1300 allows a system operator to cycle thereciprocating cam mechanism multiple times (e.g., 30-40 times) toextract towers 50 for harvesting without having to insert a new growtower 50 at each cycle and, in a later process, insert new grow towers50 using tower shuttle mechanism 1300.

Tower shuttle mechanism 1300 comprises a track 1302, carriage assembly1304 and a servomotor 1306. Brackets 1308 mount track 1302 to anassociated grow line 202 and in a substantially parallel orientation tothe grow line 202. In the implementation shown, track 1302 extends fromthe onload (beginning) end of grow line 202 and extends along a desiredlength thereof. For example, the length of track 1302 may extend along30 to 40 grow tower positions along grow line 202. A control systemcauses servomotor 1306 to drive carriage assembly 1304 to select loadpositions along the track 1302. In some implementations, the controlsystem can be programmed to perform a tower loading process for apredetermined set of grow towers 50 (e.g., 35 grow towers) to beinserted onto grow line 202 after a batch extraction process of a set ofgrow towers to be harvested.

FIG. 14 is an elevation view showing the end of a grow line 202 and howbracket 1308 attaches track 1302 adjacent to the grow line 202. FIGS.15A and 15B show an example carriage assembly 1304. For example,carriage assembly 1304 may comprise a carriage base 1312 that movesalong track 1302 in response to controlled actuation of servomotor 1306.Bracket 1314 attaches to carriage base 1312 as shown and includes pawlmember 1316 pivotally attached to bracket 1314. Stop 1318 prevents pawl1316 from rotating when it engages a grow tower moving in the forwarddirection (to the left relative to FIG. 15B). Pawl 1316, however,ratchets over a hook 52 of a grow tower 50 when moving in the reversedirection. As FIG. 14 illustrates, the path of pawl 1316 is adjacent tocams 602 of the reciprocating cam mechanism that indexes the grow towers50 along grow line 202. Whereas cams 602 engage over the center of hook52, pawl 1316 engages hook 52 at a lateral portion closer to the outeredge. In one implementation, track 1302 and carriage base 1312 can be abelt-driven actuator. The MSA series of actuators offered by MacronDynamics, Inc. of Croydon, Pa. are examples of belt-driven actuatorssuitable for use in various implementations disclosed herein.

FIG. 13 illustrates a first grow tower 50 a at a load position (p0). Asdiscussed above, a linear actuator may push a new grow tower 50 fromload transfer conveyance mechanism 47 onto a select grow line 202 at theload position (p0). Tower shuttle mechanism 1300 can be controlled tomove pawl 1316 back over hook 52 of grow tower 50 a and then forward toa desired tower position (p1, p2, etc.) along grow line 202. In oneimplementation, a control system causes tower shuttle mechanism 1300 tomove grow tower 50 a to the furthest open position along grow line 202.As the grow tower 50 a is pushed along grow line 202, cams 602 ratchetupward to allow grow tower 50 a to pass. If the reciprocating cammechanism has been cycled to off load 35 grow towers from the end ofgrow line 202, the tower shuttle mechanism 1300 will push grow tower 50a to the 35^(th) grow tower position (p35) along grow line 202. Acontrol system can be programmed to repeat this process for theremaining 34 grow towers in a loading cycle with each target loadposition being decremented as a grow tower is loaded into the desiredload position.

As discussed above, each grow tower load position (except for loadposition p0) includes an aperture or emitter where the irrigation systemsupplies solution to the funnel structure of hook 52. Ideally, when at agiven tower position, each grow tower 50 is positioned such that thefunnel structure is centered under the corresponding aperture oremitter. In one implementation, tower shuttle mechanism 1300 isconfigured to place a grow tower 50 at this ideal location for a givengrow tower position. It has been found, however, that tower shuttlemechanism 1300 may cause grow towers 50 to slide past this ideallocation. To account for this possibility, tower shuttle mechanism 1300can be configured to place each grow tower a programmed distance (forexample, 0.5 inches) short of the center or ideal position for eachtower position. In this position, the hook 52 of a grow tower 50 has notratcheted completely under a cam 602 corresponding to a given loadposition. After all tower positions have been filled, the reciprocatingcam mechanism can be controlled to perform a so-called datum sequence toposition the newly loaded grow towers 50 at the respective desiredlocations. The datum sequence does not involve a full stroke of thereciprocating cam mechanism. The datum sequence stroke is sufficient forcams 602 corresponding to the load positions (p1-p35, for example) toratchet over the newly loaded grow towers during the back stroke.However, the datum sequence back stroke is not long enough to cause cams602 for subsequent load positions (e.g., load position p36, etc.) toratchet over (and, therefore, engage) a grow tower 50 from a prior loadposition (e.g., load position p35). During the forward stroke, thereciprocating cam mechanism pushes the newly loaded towers 50 forward totheir respective centered or ideal positions along grow line 202. Thecams 602 associated with already loaded grow towers 50 (e.g., loadpositions p36 et seq. in this didactic example) move away from therespective grow towers 50 during this shorter back stroke and thentoward the grow towers 50 during the forward stroke of the datumsequence without substantially moving them.

Other implementations are possible. For example, tower shuttle mechanism1300 can be configured to engage a grow tower 50 directly from acarriage 1202 of load transfer conveyance mechanism 47 and place it ongrow line 202. In one implementation, load transfer conveyance mechanism47 positions carriage 1202 such that a 1-3 millimeter gap exists betweenreceiver 1204 and the end of a select grow line 202. Pawl 1316 pullshook 52 over this gap from receiver 1204 onto grow line 202.

In addition, pawl 1316 can be replaced by an actuated pawl or otherstructure that selectively retracts (to slide past the back end of hook52 in the reverse direction) and extends to engage a grow tower 50 toslide it along grow line 202, as carriage assembly 1304 is moved alongtrack 1302. For example, FIG. 16 illustrates an alternativeimplementation having an actuated pawl 1616. Carriage base 1612 isslidably mounted to track 1302 and is actuated as discussed above. Pawl1616 is rotatably attached to carriage arm 1613 by pin 1618. As FIG. 16shows, an actuator 1614 mounted to carriage base 1612 can be selectivelycontrolled to push against member 1620 of pawl 1616, causing the end1622 of pawl 1616 to rotate upwardly. Displacement of pawl 1616 in thismanner allows the shuttle mechanism to move past grow towers 50 alreadyplaced in the grow line 202. When pawl is moving in the forwarddirection and engaging a grow tower 50, member 1620 abuts against theend of actuator 1614 to hold pawl 1616 in position. The actuator 1614can be selectively actuated to move the pawl 1616 over a grow tower 50in a loading position, and then retracted to move the pawl 1616 into anengagement position relative to that grow tower 50 before a loadingoperation. Actuation of pawl 1616 also allows the shuttle to inspect(such as determining their position on grow line 202 or measuring someother attribute of interest) the grow towers 50 without disturbing theirpositions and allows shuttle mechanism to be used to adjust the positionof grow towers 50 already positioned in a grow line 202.

Although the disclosure may not expressly disclose that some embodimentsor features described herein may be combined with other embodiments orfeatures described herein, this disclosure should be read to describeany such combinations that would be practicable by one of ordinary skillin the art. Unless otherwise indicated herein, the term “include” shallmean “include, without limitation,” and the term “or” shall meannon-exclusive “or” in the manner of “and/or.”

Those skilled in the art will recognize that, in some embodiments, someof the operations described herein may be performed by humanimplementation, or through a combination of automated and manual means.When an operation is not fully automated, appropriate components ofembodiments of the disclosure may, for example, receive the results ofhuman performance of the operations rather than generate results throughits own operational capabilities.

All references, articles, publications, patents, patent publications,and patent applications cited herein are incorporated by reference intheir entireties for all purposes to the extent they are notinconsistent with embodiments of the disclosure expressly describedherein. However, mention of any reference, article, publication, patent,patent publication, and patent application cited herein is not, andshould not be taken as an acknowledgment or any form of suggestion thatthey constitute valid prior art or form part of the common generalknowledge in any country in the world, or that they are discloseessential matter.

Several features and aspects of the present invention have beenillustrated and described in detail with reference to particularembodiments by way of example only, and not by way of limitation. Thoseof skill in the art will appreciate that alternative implementations andvarious modifications to the disclosed embodiments are within the scopeand contemplation of the present disclosure. Therefore, it is intendedthat the invention be considered as limited only by the scope of theappended claims.

What is claimed is:
 1. A crop production system for controlledenvironment agriculture, comprising: one or more grow lines, each of theone or more grow lines comprising a grow conveyance mechanism and atower shuttle system; and a plurality of grow towers, each of theplurality of grow towers vertically attached to, and moveable along, arespective one of the one or more grow lines; wherein each growconveyance mechanism comprises: a common beam disposed in a track, thetrack extending in a direction parallel to the grow line; an actuatorattached to the common beam, wherein the actuator is operative to movethe common beam along the track in a forward stroke and a back stroke;and a plurality of cam members pivotally attached at select positionsalong the common beam, wherein each cam member is mounted to limitrotation of the cam member during the forward stroke causing the cammember to engage and push a first grow tower forward in a firstdirection during the forward stroke and to allow the cam member to slideover a second grow tower during the back stroke; wherein the selectpositions of the plurality of cam members are each configured such thatin a forward stroke a respective cam member engages a first grow towerduring the forward stroke and ratchets over a second grow tower adjacentto the first tower during the back stroke; and wherein each towershuttle system comprises a track mounted proximal to and extendingparallel to the grow line; a carriage attached to the track; an actuatorconfigured to cause the carriage to slide along the track; and anengagement member attached to the carriage and configured to releasablyengage a grow tower; and a control system operative to cause theengagement member to engage the grow tower at a load position and causethe carriage to slide the grow tower to a select position along the growline.
 2. The crop production system of claim 1 wherein the engagementmember comprises a pawl pivotally attached to the carriage, wherein whentraveling in a forward direction, the pawl engages a grow tower andslides the grow tower along the grow line and, when traveling in abackward direction, the pawl ratchets over a second grow tower locatedin a loading position.
 3. The crop production system of claim 1 whereinthe engagement member comprises a pawl pivotally attached to thecarriage, and a pawl actuator operative to engage the pawl, wherein thepawl is configured such that, when traveling in a forward direction, thepawl engages a grow tower and slides the grow tower along the grow lineand, when traveling in a backward direction, the pawl actuator moves thepawl upwardly to allow the pawl to move over a second grow tower locatedin a loading position.
 4. The crop production system of claim 1 whereinthe spacing of the select positions increases in the first directionsuch that spacing of the grow towers increases as such grow towers arepushed along the one or more grow lines with successive cycles of theactuator.
 5. The crop production system of claim 1 wherein the commonbeam has a u-shaped profile having first and second walls extending froma base, and wherein the plurality of cam members are each mounted at theselect positions along the first and second walls.
 6. The cropproduction system of claim 1 wherein each of the plurality of growtowers comprises a hook attached to the top of the grow tower, whereinthe hook is configured to engage the grow line.
 7. The crop productionsystem of claim 6 wherein each of the one or more grow lines includes agroove region to which the hook of a grow tower slidably attaches. 8.The crop production system of claim 1 wherein each of the plurality ofgrow towers comprises a first plurality of plug containers arrangedalong a first face of the grow tower.
 9. The crop production system ofclaim 8 wherein each of the plurality of grow towers comprises a secondplurality of plug containers arranged along a second face of the growtower, wherein the second face is opposite to the first face.
 10. Thecrop production system of claim 1 further comprising an onloadingmechanism comprising a power and free conveyer and one or morecarriages; wherein the one or more carriages are configured toreleasably engage grow towers; and wherein the power and free conveyeris configured to insert a grow towers on a selected grow line of the oneor more grow lines.
 11. The crop production system of claim 5 whereinthe common beam comprises a first beam section, a second beam section,and an expansion joint attached to opposing ends of the first and secondbeam sections, wherein the expansion joint is movable from a collapsedposition to an open position and configured such that, during theforward stroke, the expansion joint moves from the collapsed position tothe open position thereby causing the first beam section to move forwardwhile the second beam section remains stationary until the expansionjoint is in the open position and, during the back stroke, the expansionjoint moves from the open position to the collapsed position.
 12. Thecrop production system of claim 1 further comprising an irrigationsystem operative to supply a fluid to respective tops ends of theplurality of grow towers at one or more of the select positions alongthe grow line; and wherein each of the plurality of grow towerscomprises a tower body and a funnel disposed on the top of the towerbody, the funnel configured to direct fluid flowing therethrough over adesired region within the tower body.
 13. The crop production system ofclaim 1 wherein the select position is offset from a second position;and wherein the control system is operative to cause the grow conveyancemechanism to implement a datum sequence to move a grow tower from theselect position to the second position.
 14. The crop production systemof claim 12 wherein the irrigation system comprises one or moreirrigation lines including openings located proximally over the selectpositions.
 15. The crop production system of claim 12 wherein each ofthe grow towers comprises a plurality of plug containers disposed alongthe tower body.
 16. The crop production system of claim 15 wherein eachof the plurality of grow towers comprises a first plurality of plugcontainers arranged along a first face of the grow tower.
 17. The cropproduction system of claim 16 wherein each of the plurality of growtowers comprises a second plurality of plug containers arranged along asecond face of the grow tower, wherein the second face is opposite tothe first face, and wherein each of the plurality of grow towersincludes a central wall defining a first cavity containing the firstplurality of plug containers and a second cavity containing the secondplurality of plug containers.
 18. The crop production system of claim 17wherein each funnel comprises a collector; first and second passagewaysin fluid communication with the collector; a first slot disposed in thecollector and in the fluid communication path between the collector andthe first passageway; and a second slot disposed in the collector troughand in the fluid communication path between the collector trough and thesecond passageway; wherein the first and second slots are arranged tocause fluid to accumulate in the collector trough and distribute thefluid substantially evenly to the first and second passageways, thefirst passageway in fluid communication with the first cavity, and thesecond passageway in fluid communication with the second cavity.
 19. Thecrop production system of claim 12 wherein the spacing of the selectpositions increase in a first direction such that spacing of the growtowers increases as such grow towers are pushed along the grow line. 20.The crop production system of claim 12 wherein each of the plurality ofgrow towers comprises a hook attached to the top of the grow tower,wherein the hook is configured to engage the grow line.
 21. The cropproduction system of claim 20 wherein each of the grow lines includes agroove region to which the hook of a grow tower slidably attaches.
 22. Amethod of operating the crop production system of claim 1 comprisingactuating the grow conveyance mechanism a plurality of cycles to extracta corresponding plurality of grow towers from the grow line in a firstbatch process; and actuating the tower shuttle mechanism to load asecond plurality of grow towers onto the grow line during a second batchprocess after the first batch process.